Array modifier is scaling objects for seemingly no reason
The array modifier's object offset offsets each copy by the location, rotation and scale difference the object and the target, the empty in this case, have. You object has an uneven scale that is less than one, and since the empty has larger scale than the object, the object is scaled up for each copy.
Hit CtrlA -> apply scale to set the object's scale to 1 on all axes and the scale won't change. Also for doing circle arrays, there should not be difference in location, else each copy of the object will also move by some offset. You can apply the location of the object as well to move the object's origin to the scene center.